Dental chair unit



Feb? 1950 c. w. JOHNSON ET AL- 2,498,550

DENTAL CHAIR UNIT 2 Sheets-Sheet 1 Filed March '8, 1947 ii I w 13 45 45 Fun I..."

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Patented Feb. 21, 1950 DENTAL CHAIR UNIT Carroll W. Johnson, Chicago, and John T. Clark, Cicero, 111.

Application March 8, 1947, Serial No. 733,340

9 Claims.

This invention relates to an improvement in operator supports for use with chairs in which. a patient or subject is seated.

One purpose is to provide a support upon which an operator, such as a dentist, may rest his weight or be seated while he is working upon a patient.

Another purpose is to provide such a support in which the dentist or other operator may readily change his position in relation to the patient. while operating on the patient.

Another purpose is to provide an improved base and support associated, for example, with a dentist chair.

Another purpose is to provide such a support which is readily adjustable about and toward and away from such a chair.

Another purpose is to provide such a support which has associated with it efficient control means for operating mechanisms; for example, electrically operated mechanisms used in dentistry.

Another purpose is to provide an improved support which may be used in any situation where a patient or subject is seated or positioned at a generally fixed point, and where the operator, for example a dentist, surgeon or barber, may freely move himself in relation to the patient or subject, with a minimum of effort, and with a continuous control of various mechanisms employed upon the patient or subject.

Another purpose is to provide an improved assembly or layout in which the operator has ready access both to the patient or subject in a chair, and to other mechanisms, or adjacent furniture.

Another purpose is to provide an improved means for adjusting a seat toward and away from a dental chair.

Another purpose is to provide an improved supporting connection for a dental seat and control assembly, whereby it may be readily adjusted toward and away from the dental chair on which the patient sits.

Other purposes will appear from time to time in the course of the specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawings wherein:

Figure 1 is a perspective View illustrating the invention in position in a dentists office;

Figure 2 is a partial horizontal section on an enlarged scale, illustrating the structure of the invention;

Figure 3 is a view of the structure shown in Figure 2, with parts in elevation and parts in vertical section;

Figure 4 is a section on the line 4-4 of Figure 1, on an enlarged scale, illustrating the seat in different positions;

Figure 5 is a section on the line 5-5 of Figure 1, on an enlarged scale;

Figure 6 is a detail; and

Figure 7 is a section, on an enlarged scale, on the line 11 of Figure 3.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, 1 generally indicates the floor of a room, such as a dental office, and 2 indicates walls. 3 and 4 indicate various dental equipment. cabinets and the like. 5 in dicates a support for dental equipment, located adjacent the dental chair, generally indicated as 6. The dental chair has a pedestal which rests on or includes a base 8 which may have a generally circular bottom contour, a shown in Figure 2.

Adapted for insertion beneath the base 8, and adapted to be held in position by the weight of the base 8, is a base plate 9, the contour or the plane of which is illustrated in Figure 2. The plate 9 preferably has an outer enlargement It which may have an arcuate edge H, conforming generally to the are or curvature of the exterior edge of the base flange 8 of the chair. The members 8 and Ill may, if desired, have substantially the same elevation above the floor.

Upstandin from the portion 10, we illustrate a pivot pin l2. Rotatable about the pin is a seat and control supporting assembly which includes the hub it, the connecting arm it and the seat support Hi. The parts l3, l4 and i5 may constitute a single piece, such as a die casting. The arm I l connects the upper parts of the elements it and Hi. The hollow end enlargement l5 has an upward projection it which terminates in a sleeve ll having an internal bore l8. Adjustable in the bore !8 is the vertical seat supportin rod I9. The rod is provided with a plurality of notches or apertures 28, which are vertically aligned along the rod and which are adapted to receive a locking pin 2!. The pin 2| is mounted for endwise manual movement in the sleeve 22. 23 indicates an external manual control member whereby the pin 2! may be outwardly drawn against the compression of the coil spring 24. The spring 24 may be compressed between the pin abutment 25 and the outer end 26 of the sleeve 22. It is effective normally to urge the pin in the locking position in which it is shown in Figure 3. The rod It may be raised to any desired height, within the range of the apertures or notches 2i), and may be held locked in the desired position of adjustment, as illustrated in Figure 3. The lower portion of the enlargement l5 carries a plurality of groundengaging rollers 28. Each roller may have a pin 29, the ends of which are mounted or journaled, in suitable wall or supporting portions, as at 30 and 3!. Thus the outer end of the 3 seat supporting assembly is movably supported by the rollers 28 upon the floor surface i. It will be understood, however, that any suitable antifrictional supporting means may be employed, rollers constituting a satisfactory solution of the problem.

Mounted at the upper end of the rod i9 is an eccentrically positioned seat disc 35, merely shown as mounted on or secured to a rotatable fitting 36 which is held in position by any suitable screw or bolt 3'1. 38 is any suitable flexible seat covering, secured about the edges of the disc 35. 39 indicates any suitable upholstery padding, and 48 a protecting covering to prevent access of the upholstery to the bearing connection between the fitting 35 and the recessed or offset top of the rod l9. It will be understood, as shown in Figure 4, that the user can adjust the effective distance of the seat from the dental chair by merely rotating it about the rod l9.

We find it desirable to provide a control box which is mounted in a position convenient to the foot of the operator, and which may rotate with and still be adjustable in relation to the above-described seat assembly. We illustrate,

for example, the control box d mounted on an arm d6 which includes an inner hub portion 4? in the form of a sleeve having a cylindrical hollow 38. 49 is a pivot pin, shown as secured to an upper portion of the member 43, or an adjacent part of the arm I4. Secured to the lower surface of the arm l iis an abutment plate, shown in Figures 5 and '7 and indicated at 58. It may be held in position, for example, by screws 5i and is provided with a plurality of generally radially extending concavities or notches 52. In the upper exterior surface of the sleeve ll is an opposed plate 53, shown in Figure 6 as held in position by screws 54. It is provided with a pair of diametrically continuous ridges 55. The pin Q9 terminates in a lower head 55 which serves as a lower abutment for a coil spring 57. The coil spring tends normally to urge the sleeve 4'! upwardly against the plate 5%. However, the compression is sufiicient to prevent the user from imparting an adjusting rotation to the arm 46 and the control box 45. t will be understood that in practice it is important that unintended movement of the control box d5 be prevented, but that it may be fairly easily moved by an intended movement or thrust of the foot. The box 45 may carry any suitable actuating members or levers, as at iii), the details of which do not of themselves form part of the present invention. It will be understood, however, that any suitable control switches and connections may be employed. For example, the box 45 may, if desired, be provided with supporting means, such as the roller 45a, or such supporting means may be omitted.

It will be realized that whereas a practical and operative device is herein described and illustrated, nevertheless many changes in size, shape, number and disposition of parts may be made without departing from the spirit and intent of the invention. It is therefore wished that the description and showing herein be taken as in a broad sense illustrative or diagrammatic, rather than as a limitation to the precise showing herein.

The use and operation of the invention are as follows:

In dentistry the dentist ordinarily works while standing on his feet. This involves a serious physical strain and frequently results in corns,

ill

fallen arches and other troubles of the feet, leg joints and spine. However, if the dentist employs a seat, the problem of shifting the seat in the course of his work necessitates the use of a movable seat. Whereas dentistry is now an old art, and dental equipment has reached a high degree of specialization, it has not, up to now, been possible for the dentist to find any available readily movable seat which can be practically used during his work. The present invention fills this gap and provides a seat upon which the dentist may rest a substantial part of his weight, without any sacrifice of his mobility during the work he does on his patients. With reference, for example, to Figures 1 and 4, the seat 38 may be swung at will, to adjust it toward or away from the dental chair. This adjustment may allow for difierences in the position of the patient on the chair, for the size of the dentist, and for different tasks or jobs on which the dentist is working.

The seat supporting assembly, as a whole, may be swung at will, by the feet of the dentist, to render available all of the equipment which a dentist normally usesincluding the drill and tray, not herein shown, the cabinet 4 and the extra equipment 3. The dentist can move readily about the patient throughout an arc of sufficient extent to give him complete access to the mouth of the patient from all the angles from which he normally works. The controls of the chair are within reach of the dentist at all times, as are the controls on the readily adjustable control box 45. Thus the dentist has available at all times all of the equipment he uses, and is able to maintain a seated posture without any loss of control and without any perceptible restriction of his movements. The mechanism may be set or adjusted for the size of the dentist, the location and shape of the dental chair and the needs of the particular case. Ordinarily an initial adjustment in relation to the size of the chair and the habits and convenience of dentists is enough. This adjustment includes the adjustable, eccentric center about which the support rotates, the distance of the support from the center about which it rotates, and the height of the seat 33 upon which the dentist sits.

Whereas we have described our invention as applied to a dental office, it will be understood that it will also apply, with slight changes, to the offices of oral surgeons and, in general, to offices of eye, ear, nose and throat specialists. It may also be employed by barbers and in any other situation wherein a dentist, surgeon, barber or investigator does his work upon a patent or subject seated in a predetermined position, where it is necessary for the operator to move about the patient in the course of investigation, treatment or service.

The eccentric pivoting of the seat 38, in relation to the chair, is highly advantageous, and permits complete mobility and ready access to the patient. It will be understood, of course, that the seat 38 may readily be adjusted to any desired height. a

One advantage of the assembly herein shown is that the plate 9 is thin enough to slip under the pedestal flange 8, where it will firmly be held at any desired position of adjustment. The operator, however, can adjust it about the chair, by slightly tilting the pedestal of the chair. The center of rotation of the seat assembly, as established by the pin i2, is eccentric in relation to the center of rotation of the dental chair itself.

If the operator wishes to vary the distance between the center of the dental chair and the pin l2, he merely has to tilt the chair pedestal slightly and pull the plate 9 slightly outwardly away from the center of the dental chair. We thus provide a simple but readily adjustable assembly, with a minimum of complications, and a maximum flexibility in use.

Our invention may be applied not only to dental chairs, barber chairs or the like, but to machine tools, such as lathes, where an operator has to sit as he controls machinery with which he works.

An important feature of the invention is the employment of adequate means for supporting the feet during work. The user may set the control box at the desired position and may rest his foot on the top. It will be understood that the control extends upwardly to a level above the top of the control box 45. Thus the user, by a sideward movement of his foot, may control a rheostat in the control box 45 and thereby control his drill or other equipment. The use of the roller 450. permits the control box 45 to support the entire weight of the operator, when necessary. On the other hand, if the operator moves the control box into the dotted line position of Figure 2, and prefers to stand, the control 6011, which. moves unitarily with the control 80, can be used, since the control 6011 9 may be located at the ground level.

The end horns of the member [5, as shown in Figures 2 and 3, are also available to support the feet of the operator, when the operator is resting his weight on the seat.

We may find it desirable to put the middle of the three rollers 28 at a slight angle, with its axis non-radial. This permits it to serve as a slight brake. It will also be noted that the three rollers are so positioned as to constitute a tripod or triple support which is ample to support the weight of the heaviest user.

We claim:

1. In a structure for use with dental chairs and the like, a seat support mounted for rotation about a center eccentric to the center of said dental chair, a seat adjustably mounted adjacent the outer end of said support, and a control box movably mounted on said seat support adjacent to the floor level for adjustment toward and away from said support.

2. In a structure for use with dental chairs and the like, a seat support mounted for rotation about a center eccentric to the center of said dental chair, a seat adjustably mounted adjacent the outer end of said support, a control box movably mounted on said seat support for adjustment toward and away from said support, said control box being adapted to receive and support the foot of the user, and a control member extending upwardly from said control box and having a portion extending upwardly above the general level of the top of said control box, said control box and control member being located adjacent the floor level.

3. In a structure for use with dental chairs and the like, a seat support mounted for rotation about a center eccentric to the center of said dental chair, a seat adjustably mounted adjacent the outer end of said support, a control box movably mounted on said seat support for adjustment toward and away from said support,

said control box being adapted to receive the foot of the user, and a control member extending upwardly from said control box and having an end portion extending above the top of said control box, said control box having ground-engaging, antifrictional supporting means adapted to support the weight of the user.

4. In a structure for use with dental chairs and the like, a sub-base adjustable about the edge of the base of a dental chair, a seat support mounted on said sub-base for rotation about a center eccentric to the center of said dental chair, a seat mounted adjacent the outer end of said seat support, a control box, and means swingably mounting the control box for rotation about a center adjacent the center of rotation of the seat support.

5. The structure of claim 4 characterized by and including a rotatable, eccentric mounting means for the seat.

6. The structure of claim 4 characterized by the sub-base being of substantially smaller area than the base of the dental chair and having a relatively thin portion formed and adapted to extend beneath the chair base, said supplemental base being adjustably fixed and frictionally held on the floor by the weight of the chair base when positioned beneath said chair base, and including an upwardly extending abutment formed and adapted to engage the edge of the chair base and to fix the radial distance between the axis of the stool supporting arm and the axis of the chair.

7. In a structure for use with dental chairs and the like, a sub-base adjustable about the edge of the base of a dental chair, a seat support mounted on said sub-base for rotation about a center eccentric to the center of said dental chair, a seat mounted adjacent the outer end of said seat support, a control box, and means swingably mounting the control box for rotation about a center adjacent the center of rotation of the seat support, and individual anti-frictional ground-engaging supports for the outer end of the seat support and for the control box.

8. The structure of claim 4 wherein the seat support intermediate its ends is provided with a portion disposed at an elevation such as to provide vertical clearance for the free swinging movement of the control box beneath said seat support about its center of rotation to positions of adjustment lying on opposite sides of said seat support.

9. The structure of claim 8 wherein the mounting means for the control box includes an arm member pivoted to the seat support and movable towards and away from the seat support on either side thereof.

CARROLL W. JOHNSON. JOHN T. CLARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Newton Feb. 16, 1943 

